Structural damage occurs not only during the commercial or operational operation of an aircraft. Such damage can also be caused by operatives working at the stage of the construction or final assembly of the aeronautical parts.
Thus, when an operator drops, for example, a tool on a structure, or when a driver of a motorized vehicle, moving within an assembly area, accidentally strikes a fuselage being assembled, it may be that, for various reasons, this incident is not detected such that any damage, undetectable by simple visual inspection, particularly in the case of structures made of composite materials, cannot be identified or repaired before the delivery of a subassembly, before final assembly of the structures or before delivery to the client.
It follows that, to achieve the level of reliability and quality demanded of the structures delivered, checks must be performed and that, in the case where damage is observed very late in the assembly phase, its repair results in a loss of time that can create delivery delays which are generally reflected by financial penalties borne by the aircraft manufacturer.
There are currently no technical means that make it possible, simply and automatically, in other words without the intervention of an operator, to detect and identify incidents of this type occurring within a manufacturing or assembly area and for transmitting to a control authority alert information likely to bring about the implementation of a procedure intended to assess the damage and rapidly decide on the need to proceed with a repair.
Consequently, the only measures currently implemented, apart from a systematic final inspection of all of the assembly requiring inspection means capable of detecting damage that cannot be detected by visual inspection, consists in strict procedures with the aim of making each operator responsible such that the flagging of any incident of this type, when it is noticed, is not omitted. Such procedures can, in extreme cases, include a constant visual surveillance of the manufacturing or assembly area concerned by operators assigned to this task.